OBJECTIVES: TASK 1: THE CHANGING ORBITS OF PROPELLER MOONS REMAIN UNEXPLAINED AND MAY SHED LIGHT ON THE INTERACTIONS BETWEEN DISKS AND THE EMBEDDED MASSES WITHIN THEM. WE WILL REDUCE IMAGES OF ORBITING PROPELLER MOONS FROM 2010 THROUGH THE END OF THE CASSINI MISSION AND ANALYZE THE EVOLVING PROPELLER ORBITS TO BETTER UNDERSTAND HOW AND WHY THEY ARE CHANGING. TASK 2: THE BRIGHTNESS AND FREQUENCY OF IMPACT-PRODUCED EJECTA AT SATURN S RINGS PROBE THE METEOROID POPULATION IN THE OUTER SOLAR SYSTEM AT A SIZE RANGE THAT COMPLEMENTS DUST-BASED MEASUREMENTS AND THEIR PHOTOMETRIC PROPERTIES YIELD INSIGHTS INTO THE MECHANICS OF IMPACTS ONTO ICY RINGS. WE WILL REDUCE HIGH-RESOLUTION VERY-HIGH-PHASE IMAGES FROM THE CASSINI GF AND SURVEY THEM FOR IMPACT GENERATED EJECTA CLOUDS. WE WILL ANALYZE THE DETECTED CLOUDS TO INVESTIGATE THE PARTICLE-SIZE DISTRIBUTIONS OF IMPACTORS AND OF EJECTA CLOUD PARTICLES. TASK 3: RADIAL PROFILES OF SURFACE DENSITY VISCOSITY AND PARTICLE PROPERTIES IN SATURN S RINGS ARE NEEDED TO UNDERSTAND HOW THE DISK OPERATES. THE LIMITING BEHAVIOR OF RESONANT SPIRAL WAVES HAS NOT BEEN EXPLORED AND ENIGMATIC STRUCTURES OF SEVERAL KINDS HAVE NOT BEEN FULLY CHARACTERIZED. WE WILL ASSEMBLE HIGH-RESOLUTION IMAGES FROM FOUR CASSINI GF ORBITS INTO THE HIGHEST-RESOLUTION COMPLETE RADIAL SURVEY EVER OBTAINED OF A PLANETARY RING SYSTEM. WE WILL USE THIS SURVEY TO OBTAIN SURFACE DENSITY AND VISCOSITY PROFILES FOR THE RINGS WITH GREATER FIDELITY AND COVERAGE THAN PREVIOUS WORK TO IDENTIFY YET-UNDETECTED WEAK RESONANT WAVES AND TEST THE RINGS RESPONSIVENESS TO PERTURBATIONS TO INVESTIGATE KNOWN BUT NOT UNDERSTOOD STRUCTURE AT HIGHER FIDELITY AND TO SEARCH FOR NEW FEATURES. TASK 4: AT THE VERY HIGHEST SPATIAL RESOLUTIONS (0.2 KM/PIXEL) EXISTING IMAGES FROM THE BEGINNING OF CASSINI S MISSION AT SATURN REVEALED TANTALIZING RING STRUCTURES WHOSE NATURE AND EXTENT REMAIN UNKNOWN. OTHER VERY-HIGH-RESOLUTION TARGETS HAVE BEEN IDENTIFIED DURING THE MAIN PART OF THE MISSION. WE WILL ANALYZE THE HIGHEST-FIDELITY IMAGES EVER TAKEN OF SATURN S RINGS (OBTAINED DURING THE CASSINI GF) TO INVESTIGATE THE FINE STRUCTURE OF PROPELLERS AND OTHER RING STRUCTURES. METHODS/TECHNIQUES: THE PROPOSED WORK WILL BE CARRIED OUT THROUGH IMAGE PROCESSING AND ANALYSIS ACCOMPANIED BY THEORETICAL WORK APPLYING AN UNDERSTANDING OF RING PROCESSES AND ORBITAL DYNAMICS TO INTERPRET WHAT IS SEEN IN THE IMAGES. PERCEIVED SIGNIFICANCE AND RELEVANCE: THE PROPOSED WORK WILL LEAD TO NEW UNDERSTANDING IN SEVERAL TOPICS OF BROAD INTEREST INCLUDING THE STRUCTURE OF PLANETARY RINGS THE POPULATION OF METEOROIDS IN THE OUTER SOLAR SYSTEM AND THE INTERACTIONS BETWEEN RINGS AND OBJECTS EMBEDDED WITHIN THEM. THE SPECIFIC RELEVANCE OF THE PROPOSED WORK TO THE OBJECTIVES OF THE SOLICITATION IS DISCUSSED IN THE SECTION ON "RELEVANCE."